New Satellite Engine Could Use Earth's Atmosphere to Stay in Orbit Indefinitely

A satellite engine that uses atmospheric gases as fuel shows promise in laboratory tests and modeling, but its performance on a mission remains unproven.

Choosing an orbit for a satellite involves balancing benefits and drawbacks. Very Low Earth Orbit (VLEO), which spans roughly 100 to 450 km (62 to 280 miles) above Earth, offers several advantages. Remote sensing cameras can capture sharper images, communications and radar systems need less power, and atmospheric drag helps remove inactive satellites from orbit naturally.

That same atmosphere also creates a major challenge. Even at these altitudes, air resistance slows spacecraft down, so satellites must produce thrust almost continuously to remain in orbit. Conventional propulsion systems require onboard fuel, often costly gases such as xenon.